I wouldn’t call it false. There is a new post in the topic, not a full reply, but a small action post.
A while ago a preference was added to let users choose whether the small action post, that a topic was closed should mark the topic as unread, but I am not sure it still works. I asked about it in Small post actions no longer tracked or watched but didn’t receive a reply.
I think the change in that topic is also responsible for bumps no longer mark the topic as unread